搜尋結果
Worldwide distribution of country calling codes. Regions are coloured by first digit. Country calling codes, country dial-in codes, international subscriber dialing (ISD) codes, or most commonly, telephone country codes are telephone number prefixes for reaching telephone subscribers in foreign countries or areas via international telecommunication networks.
268 7xx. 10. NANP member. Argentina. +54. 9/15. 10. All carriers: Claro, Movistar, Personal, Tuenti. 15 before the local number but after long distance area code for national calls (0 11 15 xxxx-xxxx) and 9 placed after the international access code excluding the 15 for international calls (+54 9 11 xxxx-xxxx).
- Foundations
- Early Services
- Cellular Concept
- Emergence of Automated Services
- Handheld Mobile Phone
- Early Generations
- 4G – Native IP Networks
- 5G – Cellular Mobile Communications
- Satellite Telephone
- Mobile Device Charger Standards
Predecessors
In 1693, Professor Albert Jahn and the Oakland Transcontinental Aerial Telephone and Power Company claimed to have developed a wireless telephone. They were accused of fraud and the charge was then dropped, but they do not really seem to have proceeded with production. In 1917, the Finnish inventor Eric Tigerstedt successfully filed a patent for a "pocket-size folding telephone with a very thin carbon microphone". Beginning in 1918, the German railroad system tested wireless telephony on mili...
MTS
In 1949, AT&T commercialized Mobile Telephone Service. From its start in St. Louis, Missouri, in 1946, AT&T introduced Mobile Telephone Service to one hundred towns and highway corridors by 1948. Mobile Telephone Service was a rarity with only 5,000 customers placing about 30,000 callseach week. Calls were set up manually by an operator and the user had to depress a button on the handset to speak and release the button to listen. The call subscriber equipment weighed about 80 pounds (36 kg) S...
IMTS
AT&T introduced the first major improvement to mobile telephony in 1965, giving the improved service the obvious name of Improved Mobile Telephone Service. IMTS used additional radio channels, allowing more simultaneous calls in a given geographic area, introduced customer dialing, eliminating manual call setup by an operator, and reduced the size and weight of the subscriber equipment. Despite the capacity improvement offered by IMTS, demand outstripped capacity. In agreement with state regu...
Radio Common Carrier
Radio Common Carrier or RCCwas a service introduced in the 1960s by independent telephone companies to compete against AT&T's IMTS. RCC systems used paired UHF 454/459 MHz and VHF 152/158 MHz frequencies near those used by IMTS. RCC based services were provided until the 1980s when cellular AMPS systems made RCC equipment obsolete. Some RCC systems were designed to allow customers of adjacent carriers to use their facilities, but equipment used by RCCs did not allow the equivalent of modern "...
In December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in vehicles. At this stage, the technology to implement these ideas did not exist, nor had the frequencies been allocated. Two decades would pass before Richard H. Frenkiel, Joel S. Engel and Philip T. Porter of Bell Labs expanded the...
The first fully automated mobile phone system for vehicles was launched in Sweden in 1956. Named MTA (Mobiltelefonisystem A), it allowed calls to be made and received in the car using a rotary dial. The car phone could also be paged. Calls from the car were direct dial, whereas incoming calls required an operator to locate the nearest base station ...
Prior to 1973, mobile telephony was limited to phones installed in cars and other vehicles. The first portable cellular phone commercially available for use on a cellular network was developed by E.F. Johnson and Millicom, Inc.It was introduced by Millicom subsidiary Comvik in Sweden in September 1981. Motorola was the first company to produce a ha...
Newer technology has been developed and rolled out in a series of waves or generations. The "generation" terminology only became widely used when 3G was launched, but is now used retrospectively when referring to the earlier systems.
By 2009, it had become clear that, at some point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications, such as streaming media. Consequently, the industry began looking to data-optimized fourth-generation (4G) technologies, with the promise of speed improvements up to ten-fold over existing 3G technologies. The first ...
Deployment of fifth-generation (5G) cellular networks commenced worldwide in 2019. The term "5G" was originally used in research papers and projects to denote the next major phase in mobile telecommunication standards beyond the 4G/IMT-Advanced standards. The 3GPP defines 5G as any system that adheres to the 5G NR (5G New Radio) standard. 5G can be...
A satellite phone is a type of mobile phone that connects to other phones or the telephone network by radio link through satellites orbiting the Earth instead of terrestrial cell sites, as cellphones do. Therefore, they can work in most geographic locations on the Earth's surface, as long as open sky and the line-of-sight between the phone and the ...
Before a universal charger standard was agreed upon in the late 2000s, users needed an adapter which was often proprietary by brand or manufacturer to charge their battery. Later, mobile phones from major brands typically used a USB cable with a micro-USB or, since the mid-2010s, USB-C interface. Apple's iPhone was the sole major brand to retain it...
Taiwan,[II][k] officially the Republic of China (ROC),[I][l] is a country[27] in East Asia.[o] It is located at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northeast, and the Philippines to the south. The territories controlled by the ...
The £ grapheme in a selection of fonts. The pound sign ( £) is the symbol for the pound unit of sterling – the currency of the United Kingdom and its associated Crown Dependencies and British Overseas Territories and previously of Great Britain and of the Kingdom of England. The same symbol is used for other currencies called pound, such as ...
129,000–226,000. On 6 and 9 August 1945, the United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki. The bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the only use of nuclear weapons in an armed conflict. Japan surrendered to the Allies on 15 August, six days ...
A Bluetooth earbud, an earphone and microphone that communicates with a cellphone using the Bluetooth protocol. Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission ...
